Malus domestica ADF1 severs actin filaments in growing pollen tubes

2017 ◽  
Vol 44 (4) ◽  
pp. 455 ◽  
Author(s):  
Qing Yang ◽  
ShengNan Wang ◽  
ChuanBao Wu ◽  
QiuLei Zhang ◽  
Yi Zhang ◽  
...  

A dynamic actin cytoskeleton is essential for pollen tube growth and germination. However, the molecular mechanism that determines the organisation of the actin cytoskeleton in pollen remains poorly understood. ADF modulates the structure and dynamics of actin filaments and influences the higher-order organisation of the actin cytoskeleton in eukaryotic cells. Members of the ADF family have been shown to have important functions in pollen tube growth. However, the role of this gene family remains largely unknown in apple (Malus domestica Borkh.). In this study, we identified seven ADFs in the apple genome. Phylogenetic analysis showed that MdADF1 clusters with Arabidopsis thaliana (L.) Heynh. AtADF7, ADF8, ADF10 and AtADF11. We performed sequence alignments and analysed the domain structures of the seven MdADF proteins and identified the chromosome locations of the encoding genes. We cloned the gene encoding MdADF1 from ‘Ralls Janet’ apple and found that it was strongly expressed in pollen. Biochemical assays revealed that MdADF1 directly bound to and severed F-actin under low Ca2+ conditions. We demonstrated that knockdown of MdADF1 inhibited pollen tube growth and reduced the pollen germination rate, but rendered the pollen insensitive to treatment with Latrunculin B, an actin depolymerising agent. Taken together, our results provide insight into the function of MdADF1 and serve as a reference for studies of ADF in other plants.

2021 ◽  
Author(s):  
Patrick Duckney ◽  
Johan T. Kroon ◽  
Martin R. Dixon ◽  
Timothy J. Hawkins ◽  
Michael J. Deeks ◽  
...  

2015 ◽  
Vol 27 (4) ◽  
pp. 1140-1161 ◽  
Author(s):  
Zhenzhen Zhou ◽  
Haifan Shi ◽  
Binqing Chen ◽  
Ruihui Zhang ◽  
Shanjin Huang ◽  
...  

2013 ◽  
Vol 25 (9) ◽  
pp. 3405-3423 ◽  
Author(s):  
Yiyan Zheng ◽  
Yurong Xie ◽  
Yuxiang Jiang ◽  
Xiaolu Qu ◽  
Shanjin Huang

2006 ◽  
Vol 33 (1) ◽  
pp. 1 ◽  
Author(s):  
Catherine M. Cox ◽  
Stephen M. Swain

In Arabidopsis, as in the majority of flowering plants, developing seeds promote fruit growth. One method to investigate this interaction is to use plants with reduced seed set and determine the effect on fruit growth. Plants homozygous for a transgene designed to ectopically express a gene encoding a gibberellin-deactivating enzyme exhibit reduced pollen tube elongation, suggesting that the plant hormone gibberellin is required for this process. Reduced pollen tube growth causes reduced seed set and decreased silique (fruit) size, and this genotype is used to explore the relationship between seed set and fruit elongation. A detailed analysis of seed set in the transgenic line reveals that reduced pollen tube growth decreases the probability of each ovule being fertilised. This effect becomes progressively more severe as the distance between the stigma and the ovule increases, revealing the complex biology underlying seed fertilisation. In terms of seed-promoted fruit growth, major localised and minor non-localised components that contribute to final silique length can be identified. This result demonstrates that despite the relatively small size of the fruit and associated structures, Arabidopsis can be used as a model to investigate fundamental questions in fruit physiology.


ISRN Agronomy ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Badii Gaaliche ◽  
Afifa Majdoub ◽  
Mehdi Trad ◽  
Messaoud Mars

The evaluation of pollen viability and its germination capacity are two essential criteria for pollinator’s characterization. This study was carried out to evaluate pollen quality of eight caprifigs grown in the center-east and north-west of Tunisia. Two colorimetric tests 2,3,5-triphenyl tetrazolium chloride (TTC) and acetocarmine were used to estimate pollen viability. Germination rate and pollen tube growth in a culture medium containing 5% sucrose, 5 ppm boric acid (H3BO3) and 1% agar were registered after 24, 48, and 72 hours (H) of incubation. Results showed that the highest pollen viability rate (84%) was obtained by TTC test in caprifig Assafri, followed by Jrani (80.2%), Djebba 2 (77.8%), and Djebba 1 (73.6%). That of other caprifigs did not exceed 50% for the two tests. In all caprifig types, germination rate and pollen tube growth varied according to the incubation period. The highest percentage of germination (72%) and maximum pollen tube length (960 μm) were recorded after 72 H of incubation in caprifigs Assafri and Jrani, respectively. Among the caprifigs studied, four types (Assafri, Jrani, Djebba 1, and Djebba 2) appeared to be suitable pollinators with respect to the criteria investigated.


2017 ◽  
Vol 10 (7) ◽  
pp. 930-947 ◽  
Author(s):  
Xiaolu Qu ◽  
Ruihui Zhang ◽  
Meng Zhang ◽  
Min Diao ◽  
Yongbiao Xue ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document